Along with increased practical uses of variable voltage variable frequency inverter devices and other devices, application fields of various kinds of power conversion device have been developed.
For example, technologies applied to a boost/buck converter have been actively developed for a power conversion device in recent years. Meanwhile, wide band-gap semiconductor elements and other elements containing silicon carbide or other materials as its material have also been actively developed. In regard to such novel elements, elements having a high breakdown voltage but a small current capacity (permissible current effective value) have been put into practical use mainly for rectifiers (see, for example, Patent Literature 1).